How can I convince my parents to let me stay home with another relative? Please help?

I am going on vacation to Milwaukee next Friday, but I don't want to go because I have gallstones and can't go. I feel worried that if I tell my parents that, I feel worried that my parents would do what one of my mom's friends does with one of her kids, which is to hire a home health aide even though I only want to stay at home with another relative. I feel worried that if I tell my parents that I have gallstones and can't go, I feel worried that my parents would treat me like a toddler if I tell my parents that I have gallstones and can't go. On Friends, they aren't going on vacation with their family on Friends because they don't live at their parents' house anymore on Friends because they got jobs and moved out on Friends. The only reasons why I don't want to go on vacation next Friday are because I really want to watch my grandparents' TV, I have summer homework to do, and I have gallstones and can't go. Two of my friends from church are not going because they are going away for school soon, and two of my friends from church can stay home by themselves. How can I convince my parents to let me stay home with another relative? Can you help?

Thanks.